Surgical management of cross-bites in orthognathic surgery: Surgically assisted rapid maxillary expansion (SARME) versus two-piece maxilla

Abstract

Purpose: The surgical treatment of cross-bites includes surgically-assisted maxillary expansion (SARME) or maxillary-bipartition during bimaxillary surgery. This study evaluates and compares the changes in the teeth and lower nasal passage, as well as the stability of the expansion.

Patients and methods: The measurements were performed on the cone-beam computed tomography (CBCT) scans of 32 patients with transverse (width) deficiencies of the maxilla. To expand the maxilla, 12 patients underwent the two-piece maxilla method, while 20 patients received SARME.

Results: The mean distraction width for SARME was 6.8 mm (SD 3.7), while that for the two-piece maxilla was 4.1 mm (SD 1.6). The expansion with SARME was over the entire length of the maxilla, from anterior to posterior, whereas the expansion of the two-piece patient group was only in the posterior part of the maxilla. The segments of the maxilla opened nearly parallel in SARME, while they were reverse V-shaped in the two-piece maxilla, from anterior to posterior.

Conclusion: A key point in the planning of combined orthodontic-orthognathic therapy with surgical correction of a cross-bite is the precise determination of the area where the width needs to be increased, and the amount of correction needed to treat the patient using minimal surgical procedures.

Keywords: Distraction-osteogenesis; Maxillary-bipartition; Orthognathic surgery; Surgically assisted maxillary expansion; Two-piece maxilla.